A liquid crystal display (LCD) is a kind of widely used flat panel display. The liquid crystal display achieves gray-scale display mainly by modulating the light field intensity of the backlight via a liquid crystal switch, while achieving color display in connection with the color filtering function of an optical filter. The LCD has a variety of display modes, among which the Fringe Field Switching (FFS) mode and the Advanced Super Dimension Switch (ADS) mode are display modes having advantages such as high contrast, high transmittance, wide viewing angle and the like. In the ADS mode and FFS mode, liquid crystal molecules are rotated within a horizontal plane on the surface of the electrode, there is a great difference in the birefringence between the liquid crystal molecules, moreover, the liquid crystal molecules are arranged in a direction perpendicular to the major axes of the liquid crystal molecules, there is a great difference in the optical path difference (i.e. optical retardation) at different viewing angles (i.e. upper viewing angle, lower viewing angle, left viewing angle and right viewing angle), thus the problem of color cast is serious at a large viewing angle. In general, the incident light parallel to the major axis direction of the liquid crystal molecules is bluish, and the incident light perpendicular to the major axis direction of the liquid crystal molecules is yellowish. Therefore, there is a need to address the problem of color cast in the ADS mode.
In the prior art, the problem of color cast in the ADS mode is usually solved by dual-domain technique. Specifically, the structure of the electrode line (which is used to form an electric field that controls the deflection of liquid crystal molecules) is designed as two portions within one and the same pixel structure (the pixel structure is a dual-domain pixel structure). The two portions are an upper portion and a lower portion, which are symmetric to each other. Driven by the electrode lines, the liquid crystal molecules in the upper portion and the liquid crystal molecules in the lower portion are respectively deflected towards two directions, such that a locally symmetric structure is formed within the entire pixel structure. In this way, the color of the incident light parallel to the major axis direction of the liquid crystal molecules and the color of the incident light perpendicular to the major axis direction of the liquid crystal molecules can be partially canceled out, improving the problem of color cast.
However, since the liquid crystal molecules in the above pixel structure are arranged in accordance with the major axis, the liquid crystal molecules cannot achieve full symmetry state in the entire pixel structure, thus the influences resulting from the difference in the birefringence between the liquid crystal molecules and the difference in the optical retardation cannot be completely eliminated, and the color cast for the pixel structure at different viewing angles is still high, especially at the upper viewing angle and the lower viewing angle, hence the quality of the displayed picture is poor.